Lab Tested: AMD's Bulldozer Packs Plenty Of Cores, But Not Enough Power

Testing: Overclocking

Things haven’t boded well for Bulldozer thus far. All signs point to it being a server processor with no real place in a desktop: it’s power hungry, and performance falters in all but the most highly-threaded apps when pitted against a CPU that costs $30 less. But there’s still one plausible saving grace for the enthusiast set: overclocking.

A few months ago I’ve watched pro-overclockers take the FX-8150 well past 8GHz, so I know what it’s theoretically capable of. I’ve nowhere near that level of expertise, nor do I have giant tanks of liquid helium on hand. But it couldn’t hurt to give it a shot.

AMD provided the latest version of their Overdrive overclocking utility. It’s a wonderful tool for the performance minded, giving you full control over all of the minutiae of CPUs without requiring constant trips back to the BIOS — quite the boon for relative novices like myself.

Overclocking is more of a dark art than an exact science, so results will vary. With a few slight tweaks to the FX-8150’s CPU voltage and a bit of trial and error with the CPU multiplier, I cranked the FX-8150 from its stock voltage of 3.6GHz up to 4.4GHz — and it sang. My new Cinebench result was 7.06, an appreciable bump over its stock performance. Applications that are dependent on the CPU will see noticeable improvements.

Our gaming results didn’t change much, owing to the extreme resolutions and the powerful graphics hardware, but if you found yourself CPU limited, you could see some gains there. The tradeoff is that you’d need make the expected alterations to your machine’s configuration: slapping on a better cooler (or dealing with loud fans), and dealing with the requisite surges in power consumption.

Caveats abound, unfortunately. While AMD has made some strong claims regarding Bulldozer’s overclocking potential, much of that hinges on shutting off cores, and taking other steps to mitigate the heat and power consumption. To get things running stably at 4.4GHz, I had to disable AMD’s Turbo Core. The end result is that power consumption didn’t jump too dramatically: under load, my overclocked benchmark only drew 359 watts, as opposed to the 356 watts at stock settings. But I’d of course lost that extra edge that Turbo Core affords.